摘要:

Plasma concentrations of vasopressin and plasma renin activity were measured every 30 min for 24 h in 5 normal active humans, in 1 normal woman confined to bed (except for brief periods up to the bathroom), in 2 active patients with primary aldosteronism and in 1 patient with low-renin hypertension. Plasma vasopressin varied markedly over the day and night in a pattern suggesting episodic secretion of the hormone in the normal subjects. Assumption of upright posture was accompanied by a rise in plasma levels from undetectable to 20–50 pg/ml. Episodic secretion, however, also occurred during bed rest and sleep. In contrast, patients with primary aldosteronism and low-renin hypertension had plasma vasopressin levels considerably lower than the normals, and their profiles of plasma concentration lacked the peaks seen in normals. In the normals, although vasopressin and renin secretion often coincided, only 2 of 6 studies showed a significant correlation between the plasma levels of the two hormones. This study, therefore, shows that vasopressin is secreted periodically in normal humans, that upright posture is an important modulator of secretory activity and that the renin-angiotensin system may or may not influence the pattern of secretion. In addition, it underlines the necessity of recumbency in establishing the existence of a circadian rhythm of plasma vasopressin level

ISSN:1663-2818    

DOI:10.1159/000179011

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

The case of a true hermaphrodite, with a normal ovary and an ovotestis is presented. The ovotestis was removed and incubated in vitro with tritiated steroids (testosterone, dehydroepiandrosterone, pregnenolone and 17α-hydroxyprogesterone). Labeled metabolites were isolated and identified. Based upon these findings, a pathway of steroid biogenesis in this abnormal gonadal tissue is suggested. The ovotestis studied did not contain all the enzymes involved in ovarian steroidogenesis: 3β-hydroxysteroid dehydrogenase, isomerase, 17–20 desmolase and 17β-hydroxysteroid dehydrogenase were present, but other important enzymes, such as 16 and 17-hydroxylases, and aromatizing enzyme systems, were deficient or absent. The biosynthesis of steroids has been studied in some abnormal conditions such as testicular feminization, Klinefelter’s syndrome, polycystic ovary and cancer. In the present study, the steroid metabolism in gonadal tissue from a true hermaphrodite was investigated in vit

ISSN:1663-2818    

DOI:10.1159/000179012

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Plasma LH, FSH and testosterone were measured in testosterone-treated and untreated cryptorchid and castrated male rats. Exogenous testosterone prevented the increase in basal LH but not FSH levels seen in the untreated cryptorchids. Increases in plasma LH and FSH in response to LH-RH were greater in the cryptorchid as compared to the control group and this could not be reversed by exogenous testosterone, suggesting that spermatogenesis-related feedback factors regulate LH as well as FSH at the pituitary level in the intact rat. The results were consistent with a reduced but nevertheless significant secretion of inhibin by the cryptorchid testis. Basal plasma testosterone levels and ventral prostate weights were not significantly different from intact animals.

ISSN:1663-2818    

DOI:10.1159/000179013

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Ethynyloestradiol was administered to rabbits, guinea pigs and rats, and the concentration of the steroid in blood was measured by radioimmunoassay. In both rabbits and guinea pigs, levels of conjugated steroid were much higher than those of the freely extractable form. Whereas considerable amounts of steroid were present in a conjugated form in plasma 24 h after injection, none was present at this time in a freely extractable form. There were significant differences between young and adult rabbits and guinea pigs in the rate at which ethynyloestradiol was metabolized. The amounts present in the freely extractable form in rats were higher than in the other two species but no steroid was detected in the conjugated fraction. The results are compared with previous findings in humans.

ISSN:1663-2818    

DOI:10.1159/000179014

出版商:S. Karger AG    

年代:1979

数据来源: Karger

摘要:

Newborn pups were injected with normal saline (group A) and exogenous thyroxine (group B). Elevated T4 and decreased TSH levels from day 7 in group B continued until day 35. T4 and TSH were in normal range by day 42 and were similar to group A. Weight gain was significantly lower in group B. On day 45, half hourly injections (subcutaneous) of TRH were given to half of group A and group B each. Remaining halves were injected with saline. TSH response to TRH was significantly decreased in group B rats. Thus, neonatal hyperthyroidism results in (1) permanent decrease in pituitary reserve of TSH secretion and (2) a permanent imprinting regarding growth and thyroidal development and thus, neonatal period is critical for thyroidal development.

ISSN:1663-2818    

DOI:10.1159/000179015

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000179016

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000179017

出版商:S. Karger AG    

年代:1979

数据来源: Karger

ISSN:1663-2818    

DOI:10.1159/000179010

出版商:S. Karger AG    

年代:1979

数据来源: Karger